Carrier Access Access Navigator Network Router User Manual


 
Access Navigator - Release 1.8 August 2003 15-43
Diagnostics & Troubleshooting
Bit Patterns and Error Tests
Bit Patterns and Error Tests
NOTE: The DS1 must be set Out of Service, using the set ds1 <n> down command,
before you can use loopbacks or test patterns.
NOTE: Use the send ds1 <n> off command to turn off loopbacks and patterns.
NOTE: Sending an unframed pattern will cause a DS1 Loss of Frame (LOF).
NOTE: Put the remote CSU or NIU in line loopback mode before using this command for
BER testing. (See DS1 CSU Loopup and DS1 Network Loopup.)
NOTE: The internal Bit Error Rate Testers (BERTs) are always monitoring the DS1 inputs.
Anytime a BER test pattern is present, whether internally or externally generated, the BER for
the last one-second interval can be displayed using the status ds1 command (see Status
DS1 on page 15-13). Bit errors are also recorded in the BERT log (see BERT Log on
page 15-7).
n Send DS1 (Pattern) Off ... 15-43
n Send DS1 Line Pattern ... 15-43
n Send DS1 Payload Pattern ... 15-44
n Send DS1 Line Pattern with BER Test ... 15-46
n Send DS1 Payload Pattern with BER Test ... 15-49
Send DS1 (Pattern) Off
This command stops (turns off) all qrss and prbs test patterns sent from the Access Navigator. The
system default is off.
Syntax: send ds1 <n> off
Send DS1 Line Pattern
This command transmits an unframed test pattern to verify the quality of the DS1 signal reaching far-
end CSU equipment, such as the Access Bank II. The operator can select from several Pseudo Random
Bit Sequence (PRBS) and Quasi Random Signal Source (QRSS) patterns.
When the operator commands the selected pattern, the Access Navigator generates and transmits the
unframed pattern over the DS1. See Figure 15-23. Sending an unframed pattern will cause a DS1 Loss
of Frame (LOF) on both the Access Navigator and the remote CSU.
An external Bit Error Rate Tester (BERT) can be located anywhere on the network or at the customer
premises as shown in the figure.
When testing is complete, the send ds1 off command must be used to turn off the test pattern.